ALBERT

Description: BACKGROUND: Ibrutinib is an irreversible inhibitor of BTK in the B-cell receptor signaling cascade and is widely used to treat chronic lymphocytic leukemia (CLL) and other B-cell malignancies. Ibrutinib also inhibits the tyrosine kinase Tec in platelets, which may be one of the mechanisms of its bleeding toxicity. This makes concomitant use of anticoagulation (AC) or antiplatelet agents challenging, which is a common delimma as many patients taking ibrutinib are elderly and have increased risks of venous and arterial thromboses. The incidence of thrombosis in patients taking ibrutinib is unknown, and we hypothesized that the risk of thrombosis may be reduced during ibrutinib treatment. Therefore, we conducted a single-institution retrospective cohort study to determine the incidence and type of both arterial and venous thromboses during ibrutinib treatment and their management. METHODS: We reviewed medical records of all patients treated with ibrutinib for a hematological malignancy at the Ohio State University between 6/1/2010 and 3/31/2016. Baseline patient and disease characteristics were captured at time of starting ibrutinib. All thrombotic events occurring at any time during treatment with ibrutinib and within three days of its discontinuation were recorded. Time to thrombosis was calculated from the date of starting ibrutinib to the date of thrombosis or censored at the last assessment date, treating discontinuation of ibrutinib or death prior to thrombosis as competing risks. The cumulative incidence of thrombosis was estimated and the Fine and Gray regression models accounting for competing riskes were used to examine the association between patient characteristics and risk of thrombosis. RESULTS: The cohort included 565 patients. Median age was 65 (range 23-〉89) years and 70.3% (397/565) were men. The majority of patients had CLL (73.6%, 416/565). Other diagnoses included mantle cell lymphoma (9.9%, 56/565), indolent B-cell malignancies (8.1%, 46/565), and aggressive lymphomas (8.3%, 47/565). Median number of prior treatments was 3 (range 0-18) and 6.5% (37/565) of patients were treatment naïve. Prior to ibrutinib, 144 of 565 patients (25.5%) had a history of thrombosis. Sixty-four (11.3%, 64/565) patients had only venous thromboses, 66 (11.7% 66/565) had only arterial thromboses, and 14 patients had both. Concurrently with ibrutinib, 193 (34.2%) patients received antiplatelet agents, 16 (2.8%) patients received AC, and 31 (5.5%) patients received both. Total ibrutinib exposure for the cohort was 1,429 person-years with a median exposure of 2.39 (range 0-7.36) years per patient. A second antineoplastic agent was given with ibrutinib in 30.8% (174/565) of cases, including an immunomodulatory drug in 24 (4.2%, 24/565) patients. During ibrutinib treatment, 22 of 565 (3.9%) patients experienced 24 acute thrombotic events, mostly arterial (Table 1). The incidence of thrombosis was 1.7 (95% CI 1.1-2.5) per 100 person-years of ibrutinib exposure. Of the venous thromboses, 87.5% (7/8) were deep vein thromboses and developed at a median of 7.5 (range 0.5-75.3) months after starting ibrutinib. Of the arterial thromboses, the majority were acute cerebrovascular accidents (37.5%, 6/16) and developed at a median of 27.4 (range 0.4 - 56.6) months after starting ibrutinib. Thrombosis treatment is summarized in Table 1. After thrombosis, ibrutinib was discontinued or held in the majority of cases (75%, 18/24). One patient developed a recurrent thrombosis while on ibrutinib and AC. There were six bleeding events, 3 major (based on ISTH criteria) and 3 minor: all were taking ibrutinib and most were on AC (2 patients on antiplatelet, 1 on AC, 2 on both, 1 on neither). On univariable analysis, the only factors associated with significant (p2) increased risk of venous thrombosis were prior venous (HR 4.73, CI: 1.06-21.11) and arterial (HR 15.66, CI: 3.07-79.87) thromboses. Antiplatelet use was not significantly associated with either thrombus type. CONCLUSIONS: The cumulative incidence of thrombosis during ibrutinib treatment was low (1.7 per 100 person-years), with the majority being arterial. Prior thrombosis was associated with increased venous thrombosis risk. There are more bleeding than thrombotic complications after patients develop thromboses on ibrutinib, and optimal treatment strategies for this population requires further investigation. Disclosures Kander: AstraZeneca: Consultancy. Wang:Daiichi Sankyo: Consultancy, Other: Travel.

Description: Background Ibrutinib (IB), a nonselective Bruton's tyrosine kinase inhibitor, is associated with significantly improved disease control rates, progression free, and overall survival in several B-cell malignancies. Yet, IB's nonselective actions may result in a number of unintended adverse effects and complications that can lead to drug discontinuation. New or worsening hypertension (HTN) has been reported in 10-29% of those receiving IB within clinical trials. However, recent observational data suggest that this rate may be much higher in clinical practice and resistant to treatment. The management of IB-related HTN has not been previously well described. Furthermore, the relationship between IB-associated HTN and serious cardiovascular (CV) complications is unknown. Therefore, we sought to characterize the incidence, risk factors, management, and CV complications associated with IB-related HTN across long-term follow-up. Methods We performed a retrospective, single-center cohort study of all consecutive adult patients treated with IB for a hematologic malignancy from 2009-2016. Patient demographics, blood pressure (BP), antihypertensive therapy, cancer variables, and CV complications were collected throughout the duration of IB therapy. HTN was defined as systolic BP of ≥ 130 mmHg on 2 separate visits within 3 months. Worsened HTN was defined as an increase in HTN grade by Common Terminology Criteria for Adverse Events (CTCAE) or an increase an antihypertensive therapy. The composite of major adverse CV endpoint (MACE), including atrial fibrillation, ventricular arrhythmia, myocardial infarction, cerebrovascular accident, heart failure, and CV death, as stratified by HTN status was assessed. Univariate and multivariate Fine and Gray regression analyses accounting for competing risks of death and IB-discontinuation were preformed to determine the association between baseline covariates and outcomes, and survival analysis techniques were used to estimate the cumulative incidence of events. To assess whether any antihypertensive agent(s) was more effective in preventing IB-related HTN, the use of these agents at baseline was assessed by class, as protective factors against worsened HTN. Results Overall, 562 patients treated with IB were identified, a majority of which had CLL (73%) and were male (70%); mean age 64 ± 11 years. Sixty-two percent had preexisting HTN at the time of starting IB with 35% requiring at least one antihypertensive medication. During follow-up, 440 (78%) developed new or worsening HTN (figure 1A), with a mean increase in systolic BP of 5.2 mmHg (± 20.7). In those without baseline HTN, 72% developed new HTN while on IB, with a mean increase in systolic BP of 13.4 mmHg (± 20.1). Among patients with preexisting HTN, 82% saw worsening of their BP (mean increase in systolic BP of 4.1 mmHg (± 21.4)), including increased CTCAE grade in 77% and new antihypertensive medications in 46% of patients. Estrogen/progestin use [HR 3.47, 95% CI (1.25-9.64)] and history of diabetes [HR 1.66, 95% CI (1.03-2.66)] were risk factors for new, but not worsened HTN on multivariable analysis. MACE occurred in 19.1% of patients with new or worsened HTN, compared to 8.2% of patients with no HTN (figure 1B). In a multivariable model containing traditional HTN risk factors, new or worsened HTN was not significantly associated with MACE [HR 1.98, 95% CI (0.74-5.31)]. No specific class of antihypertensive agent was associated with the prevention of worsened HTN. Conclusion In this retrospective study, IB-therapy was associated with a substantial increase in the incidence and severity of HTN. Further research into the mechanisms, early detection strategies, optimal management, and clinical impacts of this complication are needed. Disclosures No relevant conflicts of interest to declare.

Description: Background B-cell receptor signaling inhibition (BCRi) is an effective treatment (trtmt) for patients (pts) with chronic lymphocytic leukemia (CLL), but resistance develops. Venetoclax selectively inhibits anti-apoptotic protein B-cell lymphoma 2 (BCL-2), and has demonstrated efficacy in relapsed/refractory CLL pts, particularly after BCRi. Venetoclax is started at 20 mg daily and escalated weekly over 5 weeks to the goal dose to avoid acute tumor lysis syndrome. However, we observed that many pts with relapsed/refractory CLL relapsing on BCRi progress more quickly than this schedule allows; they may progress while still taking BCRi or vigorously after its discontinuation. Given the need to promptly attain goal venetoclax dose in this population, we developed a rapid dose escalation scheme for venetoclax and reviewed our experience to understand the feasibility, safety, and efficacy of this approach in a properly equipped university setting. Methods We retrospectively evaluated adult pts with relapsed/refractory CLL presenting to The Ohio State University who were treated with a "rapid dose escalation" of venetoclax. Charts were reviewed for previous and concomitant CLL treatments, tumor burden, prognostic factors, performance status, and co-morbidities. Venetoclax dosing was planned for a shorter time period than the 5 weeks described in the label dosing. The dose was increased as quickly as tolerated following the customary doses (20mg, 50mg, 100mg, 200mg, then 400mg). We reviewed the evaluated safety and efficacy outcomes with this approach. Results We treated 34 pts with rapid venetoclax dose escalation. Median age at venetoclax start was 54 years old and were 73.5% men. Pts had a median of 5 previous CLL trtmts (range 2-18). The most recent trtmt was single-agent BCRi in 18 cases, which overlapped with venetoclax in the majority. Only 6 pts had high tumor burden and the majority had low or medium tumor burden. Cytogenetic abnormalities at venetoclax start included: 17 (50.0%) pts with 17p deletion, 5 (14.7%) with 13q deletion, 6 (17.6%) with 11q deletion, and 3 (8.8%) with trisomy 12. Fifty percent of pts had a complex karyotype, and 76.5% had unmutated IGVH status. 24 (80%, n=30 pts that had testing done) pts had confirmed BTK/PLCу2 mutations. The mean time to goal venetoclax dose was 9.6 days (range 4-31); all but 1 pt reached goal dose. Eighteen (52.9%) pts developed tumor lysis syndrome (TLS) by lab criteria at doses from 20-400 mg, 5 pts developed TLS by clinical criteria, and 1 pt experienced grade 3 severity TLS (per Cairo-Bishop definition). Only 4 pts had an elevated uric acid requiring rasburicase. Seventy-three percent of pts achieved at least a partial remission, and 4 pts each had stable or progressive disease. Three pts died within 30 days: 1 from uncontrolled bleeding and neutropenia, 1 due to neutropenic sepsis with invasive fungal infection and gastric perforation, and 1 due to neutropenic septic shock and respiratory failure. Time to best response was mean 50.7 days (range 2-428). Median time to subsequent trtmt was 279.5 days (range 73-430). 23 pts (67.6%) had not progressed at 1 year, and 26 (76.5%) were surviving at 1 year. Conclusion/summary Rapid dose escalation of venetoclax in this pt population is safe and feasible. Despite a high percentage of patients developing TLS (52.9%), all patients recovered without lasting complications and all but one were able to achieve the goal dose of venetoclax. This dosing scheme achieved disease control with 67.6% remaining progression-free at 1 year and the majority of pts surviving. It is reasonable to implement venetoclax rapid dose escalation in the proper hospital setting with ample ancillary support. This approach may be needed for CLL patients with rapidly progressive disease on BCRi. Disclosures Dotson: Abbvie: Consultancy. Bhat:Pharmacyclics: Consultancy; Janssen: Consultancy. Byrd:Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Acerta: Research Funding; BeiGene: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau; Genentech: Research Funding; Acerta: Research Funding; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Novartis: Other: Travel Expenses, Speakers Bureau. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Awan:Genentech: Consultancy; Sunesis: Consultancy; Gilead: Consultancy; Abbvie: Consultancy, Speakers Bureau; Janssen: Consultancy; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Speakers Bureau. Rogers:AbbVie: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Acerta Pharma: Consultancy. OffLabel Disclosure: Venetoclax- we will be suggesting a faster increase from starting to maximum/goal dose than the dosing label recommends. This is in order to achieve faster disease control.

Description: Background Venous thromboembolism (VTE) is the second leading cause of mortality in cancer patients. National guidelines recommend treatment with a low-molecular-weight heparin (LMWH) for at least 6 months following a cancer-associated thrombosis (CAT). The direct oral anticoagulants (DOAC) have become attractive options for the management of CAT as they are orally administered and require no routine monitoring. However, current guidelines do not support the routine use of DOAC for CAT, given the lack of direct comparison between LMWH and DOAC. The objective of this study was to compare the efficacy and safety of LMWH to DOAC for the treatment of CAT. Methods This was a retrospective, single-center study conducted at the Ohio State University. Adult cancer patients with confirmed VTE treated with therapeutic doses of either a LMWH or DOAC between December 2010 and January 2016 were included. Patients were excluded if they had a history of thrombophilia, heparin-induced thrombocytopenia, creatinine clearance (CrCl) 〈 30mL/min, required mechanical or pharmacologic thrombolysis, or anticoagulation started 〉 3 months after the initial VTE date. Medical records were reviewed for 6 months following the start of anticoagulation or until the occurrence of the primary outcome, death, or cessation of therapy. Predefined data were systematically collected, including patient demographics, treatments, risk factors, recurrent VTE, bleeding events, and death. The primary efficacy outcome was VTE recurrence at 6 months and the primary safety outcome was major bleeding at 6 months. Secondary outcomes included clinically-relevant-non-major bleeding (CRNMB), overall mortality, and risk factors for recurrent VTE or bleeding. Major bleeding and CRNMB were defined in accordance with the International Society on Thrombosis and Hemostasis criteria. Baseline characteristics were compared by t-test, Wilcoxon rank sum test, or chi-square test, as appropriate. The VTE and major bleeding outcomes were assessed by univariable logistic regression for LMWH versus DOAC and for other potential risk factors. One multivariable logistic regression model was fit to each outcome. Results Two hundred ninety patients treated with LMWH and 190 patients treated with DOAC were included. The majority of patients were treated with enoxaparin (n=287) and rivaroxaban (n=167). Mean age was 58 years, 16% had a history of VTE, 7% had a history of bleeding, and 53% had metastatic disease. Statistical differences in baseline characteristics included: high thrombotic risk cancers (57% LMWH vs 43% DOAC), hematologic cancers (19% LMWH vs 32% DOAC), vena cava filters (20% LMWH vs 12% DOAC), baseline hemoglobin and plateletcounts(10.9g/dL vs 11.4g/dL and 237 K/µL vs 252 K/µL for LMWH vs DOAC respectively). The median follow up time was 160 days and 153 days for the LMWH and DOAC groups respectively. There was no difference in the rate of recurrent VTE at 6 months between groups. Patients treated with LMWH experienced more major bleeding and CRNMB episodes and had more deaths at 6 months (Table 1).A majority of patients died from cancer progression (67% LMWH, 73% DOAC), however, 3 patients died of a major bleed (2 LMWH, 1 DOAC), and 1 LMWH patient died from recurrent PE. We used the multivariable analysis to identify several risk factors associated with increased risk of recurrent VTE: platelet count 〈 or = 150 K/µL, younger age, vena cava filter insertion after VTE, and history of warfarin failure. Risk factors associated with bleeding included the presence of vena cava filter and baselineCrCl〈 50 mL/min. In adjusted analysis, the use of LWMH showed a trend toward a higher risk of major bleeding (Table 2). Discussion In patients with CAT, we found no difference in VTE recurrence in patients treated with DOAC compared to LMWH, while LMWH was associated with increased bleeding. Baseline demographics were unbalanced and increased cancer related mortality in the LMWH group suggests more advanced disease in this group. To account for these confounding factors, we used the multivariable logistic regression model and found that LWMH is associated with a trend towards increased bleeding, although not statistically significant. Conclusion In our cohort of patients with CAT, treatment with DOAC appears to be as effective and potentially safer when compared to LMWH. Randomized controlled trials for direct comparison are ongoing and results are highly anticipated. Disclosures No relevant conflicts of interest to declare.

Description: Background Ibrutinib (IB) is Food and Drug Administration approved for chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström's macroglobulinemia (WM). High overall response rates, extended progression free survival, and an acceptable adverse event profile make IB an impactful therapy for these malignancies. Atrial fibrillation (AF) has been identified as a less common but serious adverse effect of IB with reported incidence ranging from 2-16% in clinical trials and post-marketing experience. AF can be associated with significant morbidity and mortality, including congestive heart failure and embolic events such as stroke. Data regarding the management of AF in this patient population is thus far limited. Embolic stroke prevention poses a particular clinical challenge as IB carries an inherent bleeding risk that may be increased by antiplatelet therapy and therapeutic anticoagulation. We report the management and outcomes of a large cohort of patients who developed AF while on IB therapy. Methods Patients with hematological malignancies and incident or recurrent AF while on IB therapy at the Ohio State University were identified retrospectively. Incident AF was defined as new onset AF in patients without a history AF and recurrent AF as an AF event requiring new intervention in patients with a prior history of AF. Data pertaining to patient demographics, comorbid conditions, AF events, AF management, stroke prevention strategies, and complications of AF therapy were collected. AF events were graded according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0 andcongestive heart failure, hypertension, age, diabetes mellitus, stroke (CHADs2) scores were calculated. Major bleeding was defined as a decrease in hemoglobin of 2g/dL or more, requiring a transfusion of 2 or more units of packed red blood cells or whole blood, occurring in a critical site, or contributing to death. Clinically relevant non-major bleeding events were graded according to CTCAE criteria. Management strategies and outcomes are summarized. Results Seventy-two patients with incident or recurrent AF were identified. Fifty-nine patients developed incident AF while 13 patients developed recurrent AF while on IB. Baseline characteristics are presented in Table 1.Patients with recurrent AF were older, had worse baseline ECOG performance status, and longer baseline PR interval on electrocardiogram assessment.Patients were followed for a median of 4.3 years from the start of ibrutinib and 1.7 years from AF event.Ninety-three percent of the AF events were grade 1-2 and 7% were grade 3. First-line therapy forAF included rate-control for 54 (75%) patients, interventional procedural strategies for 8 (11.1%), and rhythm-control for 3 (4.2%). Seven (9.7%) patients required no intervention. Twenty-two patients (30.5%) required a second and 4 (5.5%) required third-line AF management intervention. Among those with a secondary AF management strategy, rhythm control was the most frequently utilized (n=10, 45.5%). During the AF events, 31 (43.1%) patients continued IB, 35 (48.6%) temporarily held IB, 5 (6.9%) discontinued IB, and one patient had the dose reduced. Stroke prevention strategies are described in Table 2. Patients with recurrent AF were less likely to be treated with anticoagulation when compared to patients with incident AF. Six (8.3%) patients had a major bleeding event and 2 of these patients went on to have a second major bleed. Of the 8 major bleeding events, 3 occurred with concomitant antiplatelet therapy and no patients were on anticoagulation therapy at the time of bleeding. Eighteen (25%) patients developed a total of 25 clinically relevant non-major bleeding events (9 grade 1 events, 13 grade 2 events, 2 grade 3 events, and 1 could not be graded). Only one potential embolic event occurred in a patient with a CHADs2 score of 1 on aspirin 325mg who developed symptoms consistent with stroke. Conclusions AF events in patients being treated with IB are generally manageable and in the majority of cases did not result in IB discontinuation. Clinically relevant bleeding events are common, and caution must be exercised when initiating routine antiplatelet therapy and/or anticoagulation in patients with IB. Risk of ischemic stroke was low in our patient population, though follow up was limited. The optimum strategy for stroke prophylaxis in patients with concurrent IB is unclear. Disclosures Christian: Pharmacyclics: Research Funding; Janssen: Research Funding. Porcu:miRagen: Other: Investigator in a clinical trial; Innate Pharma: Other: Investigator in a clinical trial; celgene: Other: Investigator in a clinical trial; Millenium: Other: investigator in a clinical trial. Woyach:Morphosys: Research Funding; Karyopharm: Research Funding; Acerta: Research Funding. Jones:AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding. Awan:Innate Pharma: Research Funding; Novartis Oncology: Consultancy; Pharmacyclics: Consultancy.

Description: In a retrospective analysis, Dickerson et al report that the incidence of hypertension in patients treated with ibruitinib is nearly 80% and is associated with an increased rate of adverse cardiovascular events, primarily atrial fibrillation. Cardiac events can be reduced by treating the hypertension.

Description: Background Acalabrutinib is a highly selective second-generation Bruton's tyrosine kinase (BTK) inhibitor approved for the treatment of chronic lymphocytic leukemia (CLL) and mantle cell lymphoma. Ibrutinib, the first-generation nonselective BTK inhibitor, has been associated with cardiovascular (CV) complications including atrial fibrillation and ventricular arrhythmias, potentially related to off-target effects. In prior studies, the incidence of major adverse cardiovascular effects (MACE) with ibrutinib was 16.5-38%. With acalabrutinib being more selective, we postulate that less of these off-target effects would be seen. Although early experience with acalabrutinib suggests improved tolerability compared to ibrutinib, the long-term CV risks are unknown. Therefore, we sought to characterize the incidence, risk factors, and management of CV complications associated with acalabrutinib across long-term follow-up. Methods We performed a retrospective single-center cohort study of adult patients treated with acalabrutinib for a hematologic malignancy from January 2010 to August 2019. Patient demographics, CV and cancer variables, and CV complications were collected throughout the duration of acalabrutinib therapy. MACE was defined as cardiac arrhythmias (including atrial and ventricular arrhythmias), myocardial infarction, stroke, heart failure, and CV death. CV events, including arrhythmias, were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), and adjudicated with an independent cardiologist. Descriptive statistics were used to summarize patient characteristics, using the mean ± standard deviation (SD) or median (interquartile range) for continuous variables and frequency counts with percentages for categorical variables. Time-to-event analysis methods were used to summarize MACE outcomes and evaluate associations with these outcomes. Results Overall, 290 patients treated with acalabrutinib were identified, majority had CLL (89%), and were male (72%) with a median age of 64 years. Seventy-seven (27%) patients were previously treated with ibrutinib. Sixty-seven percent of patients had a prior cardiac history, including 49% with baseline hypertension (HTN). MACE occurred in 18 patients (6%). Atrial fibrillation was the most common event occurring in 12 patients, followed by diastolic heart failure in 3 patients. There was one ventricular arrhythmic event (0.3%). Forty-four percent of patients temporarily held acalabrutinib during the MACE event, while 50% had no change to their acalabrutinib therapy. After the event, 6% of patients discontinued acalabrutinib and 11% of patients had dose reduced to 100mg daily. Age, gender, diabetes, kidney disease, and smoking status were found to be significantly associated with MACE. The odds of MACE were 1.8 times higher for every 7-year increase in age; when looking at just atrial fibrillation, the odds were 1.58 times higher for every 7-year increase in age. The effect of current smokers compared to never smokers was not significantly associated with MACE, however the odds of MACE were 3.4 higher in former smokers compared to never smokers. In comparison to ibrutinib (Dickerson, et al. Blood, 2019), the rate of MACE was lower- 66 vs 21 events per 1,000 person-years (P

Description: BACKGROUND: Ibrutinib is an irreversible inhibitor of Burton's tyrosine kinase (BTK) in the B-cell receptor (BCR) signaling cascade and is a practice changing treatment for chronic lymphocytic leukemia (CLL) and other B-cell malignancies. Ibrutinib also inhibits Interleukin-2 Inducible Kinase (ITK) in T-cells and has demonstrated immunomodulatory effects. Recently, cases of opportunistic infections (OI) have been reported during ibrutinib treatment including pneumocystis jirovecii pneumonia (PJP), cryptococcus, and fusarium. To date there are no reports on OI in large unselected cohorts of patients taking ibrutinib. We conducted a single-institution retrospective study to determine the incidence and type of OI during ibrutinib treatment as well as outcomes and characteristics associated with risk. METHODS: We reviewed medical records of all patients treated with ibrutinib at the Ohio State University between June 1st 2010 and March 31st 2016. Patients who received ibrutinib for graft versus host disease were excluded. All charts were initially reviewed by one of the investigators and patients with OI were independently reviewed by a second investigator. Baseline patient and disease characteristics were captured at time of starting ibrutinib. All OI occurring after the first dose of ibrutinib were recorded. Onset of OI was considered as the time of first presentation for a complaint related to OI. Time to OI was calculated from the date of starting ibrutinib until the onset of OI or censored at the last assessment date, discontinuation of ibrutinib, or death prior to OI as competing risks. The cumulative incidence of OI was estimated and the Fine and Gray regression models were used to examine the association between patient characteristics and risk of OI. Covariates with significance level of p